> The phrases "known to be X [language]" are completely undefined as far as
> the current text is concerned. If you want to have one note that covers all X,
> then by all means do so, but don't just leave it in such an undefined state.
Did you follow the link? I think it's well-defined in Terminology section. The section also has examples you requested.
For the rest of feedback, I think it's a big enough issue to split the thread so I'm responding separately.
Regards,
Koji